Field of Invention
The invention relates to cellular mobile radiotelephones. More particularly, the invention relates to a system for easily obtaining the electronic serial number (ESN) and mobile telephone number (MID) of a cellular telephone.
Each cellular telephone has a unique electronic serial number which resides within internal circuitry of the telephone, and serves to identify it to the cellular network. An invoice specifying the ESN of a cellular telephone usually accompanies its purchase. In addition, some telephones have the ESN printed on the handset. A few others are designed to provide a visual display of the ESN as it has been stored in the memory of the telephone, upon proper entry of a keystroke sequence on the keypad.
In addition, manufacturers of electronic test equipment currently produce two types of devices that can be used to extract the ESN and MID from a cellular telephone. The primary function of the first type of device is to program the numeric assignment module (NAM), and hence program or read the MID, of a cellular telephone. Currently, some manufacturers produce stand-alone machines. Others supply software which a personal computer uses to program a NAM by remotely controlling a standard EPROM programmer. Retrieving the ESN of a cellular telephone is an additional capability, besides programming the NAM, that some of these machines have.
However, with both types of devices, if removal of the NAM from the cellular telephone is required in order to program it, the ESN is not retrievable. Furthermore, operation of such devices requires hard-wiring between the device and the cellular telephone.
Another type of device which can be used to obtain the ESN and MID of a cellular telephone is used primarily to examine the electromagnetic transmissions of a cellular telephone. These devices receive and analyze the data transmitted by a cellular telephone, and can be programmed to extract the telephone's ESN and MID. Operation of such devices does not require hard-wiring between the device and the cellular telephone, but does necessitate sufficient proximity between the two, and a substantial number of technical modifications to the transmission analyzing device.
All of these devices are relatively expensive. Consequently, they are not widely available. Therefore, the ESN or the MID for a telephone is often not available, or becomes lost or misplaced, leaving the agent and/or user without easy access to the most important means for identifying and servicing the telephone.
Thus, when a user changes agents or has problems using his telephone in a cellular network, absence of the ESN or the MID can result in difficulty in providing prompt, satisfactory service. For example, when a user signs up with a new agent, the agent "activates" the telephone on the agent-carrier's cellular network, thereby authorizing its use for making calls. The activation process also involves entering the user's ESN into the system records of the carrier for billing and other purposes.
If this operation is not performed correctly, i.e. the ESN that the agent logs into the system does not match the telephone internal ESN, the cellular network will not permit the user to make calls. In most cases, a telephone that has been improperly activated with the carrier, by an agent, will merely receive a prerecorded general access denial message when the user attempts to place a cellular call. Presently, the denial messages of most carriers do not indicate a specific reason for denial. Consequently a user receiving such a denial message is not certain whether a faulty ESN or some other problem is the cause.
Therefore, before a user leaves the premises of an agent, after installation or service, both the user and agent need to know that the telephone is correctly activated. Moreover, if an activation is not correct, the agent needs an easy way to verify that the ESN is correct, the proper MID has been programmed into the phone, and know that some other problem must be addressed. Presently users, agents, and carriers have no easy, inexpensive means for determining or verifying the ESN or the MID of a cellular telephone.
In addition, a variety of technical problems can prevent a telephone from operating properly. Such problems may arise from factors relating to voice modulation/demodulation, radio frequency transmit/receive functionality, DTMF modulation, call processing capability, and battery power. Another need in the art is for an easy means for users, agents, or carriers to conveniently run performance tests on a telephone.